Answer:
Radius of the convergence is R = 
and,
The Interval of convergence is 
Step-by-step explanation:
Given function : Σ(21x)^k
Now,
Using the ratio test, we have
R = 
or
R = 
or
R = 
now,
for convergence R|x| < 1
Therefore,
< 1
or

and,
Radius of the convergence is R = 
and,
The Interval of convergence is 
Answer:
1/2, 2/7, 5/6, 4/2
Step-by-step explanation:
B is the answer I think.Please make me brainlist answer!
y=3/3x+-2
Step-by-step explanation:
it goes up 3 and over 3 so its 3/3 and it starts at -2
The 5 is in the tens spot and the 8 is in the ones.
Look at chart. Plug in an 8 where it says ones, and the 5 where it says tens. Yeah?